Estimating disorder and its adverse effects in semiconductor Majorana nanowires
Estimating disorder and its adverse effects in semiconductor Majorana nanowires
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DOI：
10.1103/physrevmaterials.5.124602
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发表时间：
2021-12-09
影响因子：
3.4
通讯作者：
Das Sarma, Sankar
中科院分区：
文献类型：
--
作者：
Ahn, Seongjin;Pan, Haining;Das Sarma, Sankar
我们使用现有的传输测量文献中开发的半导体（砷化铟和锑化铟）材料，用于制造超导体半导体纳米线样品中的马约拉纳零模式的实验搜索的可能量的无序的数据集。使用估计的直接马约拉纳模拟中的障碍，我们得出结论，目前的水平在半导体马约拉纳纳米线的障碍是至少一个数量级高于拓扑马约拉纳零模式的出现所需的。与现有的结果一致，我们发现我们估计的无序导致偶尔出现的平凡零模式，这可以后选择，然后通过改变系统参数（例如，隧道势垒），导致在隧道光谱中具有类似于2 E（2）/h量级的微小零偏压电导峰。然而，大多数计算的隧道光谱在这些无序系统中，表现出基本上没有显着的功能，这也是符合目前的实验状态，零偏峰被发现只是偶尔在一些样品下仔细微调。
We use the available transport measurements in the literature to develop a dataset for the likely amount of disorder in semiconductor (InAs and InSb) materials which are used in fabricating the superconductor-semiconductor nanowire samples in the experimental search for Majorana zero modes. Using the estimated disorder in direct Majorana simulations, we conclude that the current level of disorder in semiconductor Majorana nanowires is at least an order of magnitude higher than that necessary for the emergence of topological Majorana zero modes. In agreement with existing results, we find that our estimated disorder leads to the occasional emergence of trivial zero modes, which can be post-selected and then further fine-tuned by varying system parameters (e.g., tunnel barrier), leading to trivial zero-bias conductance peaks in tunneling spectroscopy with similar to 2e(2)/h magnitude. Most calculated tunnel spectra in these disordered systems, however, manifest essentially no significant features, which is also consistent with the current experimental status, where zero-bias peaks are found only occasionally in some samples under careful fine-tuning.